The 8.8 magnitude quake and the tsunami it unleashed killed 521 people, destroyed 220,000 homes and washed away docks, riverfronts and seaside resorts.
Many of the victims came from Constitucion, where the tsunami destroyed 80 percent of the heart of the coastal city.
Sebastian Pinera began his presidential term a few days after the quake and visited Constitucion on Wednesday to showcase the reconstruction efforts under his leadership.
Bells in Constitucion tolled at 3:34 a.m. to commemorate the quake three years ago. Pinera attended a candlelight vigil and inaugurated a housing complex where eight people died after the natural disaster turned it into a ruin of flattened homes.
Damage from the quake and tsunami cost Chile $30 billion, or 18 percent of its annual gross domestic product.
The government says about 90 percent of the reconstruction is complete. But critics say the number is closer to 60 percent and many victims remain homeless.
Opposition lawmaker Patricio Hales said only 44 percent of the homes needed have been completed. But Housing Minister Rodrigo Pérez called the criticism ill-intentioned and baseless.
Charges that former President Michelle Bachelet's government failed to issue a timely tsunami warning, as well as slow reconstruction efforts under Pinera have been shaping politics ahead of November's presidential election.
Opposition lawmakers have slammed Pinera's governing center-right party for trying to link Bachelet to the failed tsunami response.